Visibly reduces pores!

Made with pride by the Voorhees Family since 1980
(just don't ask what's in it)

The shellac seal coat is about as good as I can make it.  The shellac looks smooth, flat, and the grain has suitably "popped."  So, now it's time to fill the wood grain (aka pores).

For those playing the Luthier Home Game (or any fine woodworking project) filling the wood grain helps make a project go from "nice" to "WOW!"  And anyone familiar with applying makeup can probably tell you why.

Wood, like skin, has pores.  Some woods (like maple, ebony, and rosewood) have small pores and some (like mahogany, walnut, and butternut) have large pores.  Large pores make the surface of the guitar look uneven so they are traditionally filled prior to putting a finish on the guitar.  Having said that - one of my favorite guitars was intentionally not pore filled and it looks (and sounds) fantastic.  So, like with anything art-related, do what you want.

This guitar body is made up of butternut, maple, and cocobolo.  The butternut needs pore filling (although the shellac gave me a good head start on that).  The maple needs spot filling as the top has some tear-outs and there are a couple of tiny voids in between the maple top and the binding.  The cocobolo is interesting.  Usually cocobolo has small pores (like Rosewood) but this piece of cocobolo has developed microscopic surface cracks in the 8 years that I've been building this guitar.  So, it needs a little filler.

Yummy!

Traditionally wood filler is toned to match the wood you are using.  Reddish-brown for mahogany, whitish-yellow for maple, etc.  I did try going that route once - and was unimpressed.  Whether I was unimpressed with the product or with the implementation - I'm not tellin'.

But because of that I found the above product - a clear wood filler that dries pretty transparent.
Additionally, it dries quickly - which is nice for when you only have an hour or two in the evenings to work on projects.  

Um, yeah.  Not going there.

In brief - you rub the special sauce into the body against the grain, with the grain, and in a swirling pattern to make sure the pores get filled.  You wait a couple of minutes for the filler to 'gel' or partially harden and then you trowel it off.  Kinda of like a squeegee.

I tried two different techniques for applying the pore filler.  One worked better than the other.

First up - I rubbed the filler onto one side at a time, squeegeed the excess off and then moved to the next side.  I had to wait a minute or two for each side as the filler gelled - but it worked well.

How can you not like a word like "squeegee?"

After it fully dried I sanded any remaining filler that was sitting on the surface of the wood and inspected the pores.  It was pretty clear it needed a second pass with the filler so I tried wiping the whole body with filler in the hopes that by the time I finished applying the filler it would be dry enough to squeegee off. 

What you can't see in this picture is the dust mask I'm wearing.  This stuff is worse than sawdust.

Sadly, the filler dried faster than I applied it - so when I went to trowel it off more stuck to the surface than I had intended.  Takeaway: do one side at a time.

No, seriously, don't breathe that stuff in.  Your lungs will not dig it.

Because there was so much filler on the body (and because nothing clogs up 400 grit sandpaper like pore-filler) I chose to move back down to 320 grit sandpaper in the hopes of speeding up the process.

"He chose... poorly."

Yeah...  That's not a spot of reflected light.  That's me sanding down to the bare wood.  My first thought was -

Well, my first thought wasn't really printable...

But my second thought was, "Well, at least I've done this before and I know what to do."
On my very first build I had the same thing happen (only later in the process).  It means I have another round (or two) of shellac in my future but, "so be it."

Takeaway: stick with 400 grit sandpaper when you get to this stage.  10 extra minutes of sanding is better than going back to square one.

It was at this point that Jerry got so frustrated he just started finger painting on the guitar body

I mentioned earlier that the maple top had a couple of tear-outs (more like pits) that were pretty visible.  Once I have a high-gloss finish on this you would be able to see those pits from a mile away.  So it made sense to fill those as well.  Since they were still visible after two rounds of pore filling I decided to over-fill them.  Hence the blobs of filler above.

Once these dried I sanded them flush and inspected the body.  Pretty much everything that needed to be filled was filled.  Since I had to touch up that spot I sanded through - I decided to use the last of my prepared shellac to do two more thin coats on the entire body.  I did add a little more denatured alcohol to stretch it out a bit - which made it a pretty thin "cut."  See this post if you have no idea what I'm talking about.  

So, just to recap - the finishing process for this guitar has been:

1. Finish sand the body to 400 grit sandpaper
2. Tape off the sides of the guitar
3. Dye the maple top wood
4. Sand (400 grit) the maple just enough to make the grain stand out
5. Dye the maple top wood again
6. Apply 1 coat of shellac
7. Apply 2 more coats of shellac to fix the first one that was done so poorly
8. Scuff sand (400 grit) the shellac
9. Apply 2 more coats of thin shellac
10. Scuff sand (400 grit) the shellac
11. Apply 1 last thin coat of shellac
12. pore fill
13. sand (400 grit)
14. pore fill again
15. sand with (320 grit) sandpaper (too much!)
16. spot fill maple and sand
17. 2 more coats of shellac
18. scuff sand (400 grit)

Yeesh!  And now we start the real "finishing."

Next up - Nitrocellulose Lacquer.

By the way - if you've made it to the end of this post - you deserve a prize:  Enjoy!